24-05-2021, 11:48 AM
I was not suggesting 4140 is the same as EN40b but it is of similar properties. P20 is very much used here in NZ as it is available in flats and plate which 4140 is not. P20 has superior stability and can be nitrided to .3mm in its supplied state after machining . It may prove wise to stress relieve before grinding and nitriding after machining.
Austin cranks were not very hard (fileable =57 Rockwell C) The Austin drawings state A2 as the material. This could be an internal material reference-maybe the same stuff as steering arms?
My experience has shown P20 nice to machine and finish.
What is important is to cut down the number of operations to finish the Billet with the view to affordability, wire cutting and water cutting give good results but are very expensive. I have had multiple quotes for 700 pounds (NZ$1400 ) just to profile the billet by waterjet.
I would comment that the prices paid for Phoenix ,Barlow etc cranks in the past leave little room for profit, having done my own cost analysis.
I think that Tony is doing due diligence on suppliers for good reason- Good luck and thanks to him.
Cheers Steve H.
Austin cranks were not very hard (fileable =57 Rockwell C) The Austin drawings state A2 as the material. This could be an internal material reference-maybe the same stuff as steering arms?
My experience has shown P20 nice to machine and finish.
What is important is to cut down the number of operations to finish the Billet with the view to affordability, wire cutting and water cutting give good results but are very expensive. I have had multiple quotes for 700 pounds (NZ$1400 ) just to profile the billet by waterjet.
I would comment that the prices paid for Phoenix ,Barlow etc cranks in the past leave little room for profit, having done my own cost analysis.
I think that Tony is doing due diligence on suppliers for good reason- Good luck and thanks to him.
Cheers Steve H.